The present invention relates to an improved method of lighting for colored shadows, more particularly, it relates to a method of illuminating objects by a plurality of color light sources and a white light source to utilize the effect of colored shadows of the objects wherein a ratio of illuminance by the white light source to those of the color light sources is specified so as to impart the optimum effect.
The method of lighting for colored shadows by arranging color lamps in three R, G and B groups of at least one lamp for yellow to red (R group); at least one lamp for green (G group) and at least one lamp for violet to blue (B group) and illuminating the objects is the novel method of lighting for beautifully colored shadows of the objects which is quite different from the conventional color lighting.
The inventors have found that the optimum appearance of the colored shadows can be attained by balancing illuminances obtained by color light sources in the range of ##EQU2## wherein I.sub.R designates an illuminance at the part illuminated by only the lamp in the R group in the shadow of the object to both of the lights of the lamps in the G group and the B group; I.sub.G designates an illuminance at the part illuminated by only the lamp of the G group in the shadow of the object to both of the lights of the lamps in the R group and the B group and I.sub.B designates an illuminance at the part illuminated by only the lamp in the B group in the shadow of the object to both of the lights of the lamps in the R group and the G group.
However, in the practical application, it is considered to combine a white light source with the color light sources in the three groups. In the latter case, the condition of the lighting for colored shadows is not satisfactory with the above-mentioned conditions. An improvement has been needed.